Flying in Hot Weather: Density Altitude

There’s a lot to consider when flying at high density altitude.

By Mike Adams, VP Underwriting Avemco Insurance Company

Hot weather makes getting the best possible performance a necessity. Get the maximum performance when you need it the most. Don’t stack the deck against yourself by ignoring weight and balance, taking off or landing with a tailwind, or approaching your flying with anything less than precision.

Everything’s working against you at high density altitudes. Engines produce less power (even if they’re turbocharged), and propellers are less efficient at turning power into thrust. Wings produce less lift. Even low-altitude airports can be hot enough to degrade performance. So how do you beat the heat? Start with a good check of the Takeoff Performance chart for the aircraft. Know what you can you expect, and how you need to get it, and in most cases your airplane will get you safely off the ground.

That is, unless you further stack the deck against yourself.

You might be able to get away with little things in cooler weather that you can’t when hot air robs your airplane of performance. It’s easy to “guess” at the airplane’s weight and balance, and on a cool day you can sometimes get away with it. Try it on a hot day, however, and the slim performance margin may not be enough. Same goes for distribution of the weight, if the center of gravity is too far forward or aft. Add this to hot weather and you may have too much stacked against you.

What about a little tailwind on takeoff or landing? Tailwinds add a significant amount to runway requirements both for departure and arrival. Add this to the increased length needed in hot weather and you may have a real problem. We take off and land into the wind for a reason. The airplane performs better. When hot air limits performance you need all the help you can get.

Taking off by feel might work when you’ve got gobs of performance available. Not lifting off at the right airspeed, or in the right attitude, will get you less than optimal results, but you may have the margin to spare. Take the airplane up on a hot day, however, and sloppiness may be enough extra lost performance that you find yourself in the trees.

You can be a hot pilot and still keep your cool if you don’t stack the deck against yourself.

Articles and news items provided by Avemco are not intended to provide technical or legal advice. Content is for general information and discussion only, and is not a full analysis of the matters presented. The information provided may not be applicable in all situations, and readers should always seek specific advice from the FAA and/or appropriate technical and legal experts before taking any action with respect to any matters, such as density altitude, discussed herein.